The effective removal of adhesive retention agents during the cleaning of dental prostheses that can be taken out of the mouth is of essential importance in avoiding inflammatory changes in the mucous membrane, which in turn result from the concentrated growth of bacteria and fungi in any remaining retention agent.
Many wearers (about 50-65%) of removable dental prostheses have varying degrees of difficulty with their prosthesis. (See Miller E. L., 1975, J. Dent. Assn. S. AFR. 30 (1): 89-93 and Budtz-Jorgensen E., 1978, JADA, 96, 96: 474-479). These troubles may manifest themselves in different ways, and their causes are varied.
Maintaining the prosthesis fixed in its intended position both during rest or relaxation and while speaking, and most importantly during the movements connected with chewing, may also be a problem for many people.
These inconveniences may still appear even where the prosthesis has been constructed in accordance with all of the rules pertaining to dental artistry. The reason for this may be the presence of unalterable and unfavorable anatomic oral conditions, or other individual causes, such as motoric insufficiencies in the oral region, such as near the jaw. These insufficiencies often occur with certain categories of people, such as old people and physically or mentally handicapped people. (See Norderram E., 1977: Vol. 69, No. 7). The inability to fix the prosthesis causes a feeling of insecurity in the individual, and is often a psychological handicap during social contact with other people.
It is also not unusual among denture wearers for inflammatory changes to occur in the oral mucous membrane against which the base of the prosthesis abuts. Through intensified research in this field, it has now been established that the primary cause of such disease conditions are of microbial nature, with the emphasis on the occurrence of fungi. The inflammatory conditions in the mucous membrane are thus often related to the occurrence of fungi in the base of the prosthesis itself, which is extremely difficult to overcome. (See Budtz-Jorgensen E., 1974: Scan. J. Dent. Res. 82:151).
There have been various practical solutions which have therefore been previously attempted so as to eliminate these problems. Thus, in order to improve the retention of the prosthesis, it is extremely common to apply a fixing preparation containing an adhesive or glue-like material, preferably sodium carboxy methyl cellulose, onto the surface of the prosthesis facing the oral mucous membrane, normally termed the mucous membrane surface of the prosthesis. These fixing preparations usually consist of a powder, which is applied onto the mucous membrane surface of the prosthesis, and which comes into contact with the saliva-coated or saliva-producing mucous membrane, thereby forming a gel with adhesive action. On the other hand, the prosthesis is sometimes moistened with some water before insertion into the mouth, and also in order to improve the gel formation. Fixing preparations are also available in the form of a paste, which is manufactured in a ready-to-use form. The gelling or adhesive agent of such fixing preparations is generally sodium carboxy methyl cellulose.
The method thus described enables the wearer to improve the fixing of the prosthesis in a simple manner. For this reason, it is often used. However, it has certain drawbacks, particularly if the composition is applied over long periods of time. These fixing preparations do not inhibit the bacteria and fungus flora which normally exist and in the oral cavity. To the contrary, experience has shown that they may promote the chance of colonization for these micro-organisms. Therefore, chemical inhibitors have been added to some types of fixing agents in order to prevent such growth, but these have, in turn, resulted in new problems. That is, the continued use of such chemical inhibitors may readily produce toxic and allergic reactions in the mucous membrane tissues as a result of inhibitor exposure, particularly when such use is extended over a number of years of intermittent application.
Irrespective of whether the denture wearer uses a retention composition or not, he must always carry out a careful program of oral hygiene including the daily cleansing of the prosthesis, mouth and any remaining teeth, in order to remove bacteria plaque which is continuously being produced, as well as the collection of food particles, the occurrence of which is difficult to prevent. (See Hedegard E., 1977: Vol. 69, No. 7). Apart from the more unpleasant feeling of bad odour and taste, the insufficient prosthetic and oral hygiene may give rise to a state of inflammation, or even serious alterations in the mucous membrane, known as prosthesis stomatites, and to caries attacks on the remaining teeth.
It is very difficult to remove these adhesive gels, and this therefore must be done by an active mechanical method, such as by scraping, brushing, and at the same time rinsing. In spite of this, some adhesive gel often remains, and it is very hard to detect since the gel is transparent.
In order to clean the prosthesis as efficiently and gently as possible, dentists recommend brushing with a soft brush and suitable chemical wetting agent, preferably having microbicidal properties (See Andrup B., 1977: Swed. Dent. J., Vol. 66:181).
Due to inconvenience and difficulty in removing these adhesive gels, many patients and nurses fail to execute this cleaning operation effectively, and therefore the result is a heavy remaining bacteria and fungi effection.
In connection with chemical cleansing, there are a number of compositions available which are especially intended for use with such prostheses. Basically, these cleansing compositions consist of a combination of two or more chemical substances in powder or tablet form which, when dissolved in water, vigorously react with each other, producing gas or bubbles (CO.sub.2). It is this effervescing solution which is thus intended to automatically remove the coating of bacteria plaque and remnants of fixing agent from the prosthesis when it is immersed therein, and if successful, this can be done without further mechanical cleansing.
However, there are certain disadvantages associated with this course of action. For example, this is just a one-way action in which the bubbles mechanically wear away the tacky retention agent, which is normally very hard to remove completely. Moreover, this type of cleaning agent becomes very expensive for the users.